Sand control using shape memory materials

ABSTRACT

An embodiment of a method of controlling fluid flow in a borehole in an earth formation includes: deploying a fluid flow apparatus in the borehole, the apparatus including a carrier and a shape memory component disposed at the carrier, the shape memory component including a shape memory material having a transition temperature, the shape memory material having a first shape; activating the shape memory material by causing the shape memory material to soften and change from the first shape to a second shape, the second shape configured to cause the shape memory material to control fluid flow; and deactivating the shape memory material by applying a deactivation fluid to the shape memory material, the deactivation fluid configured to cause the shape memory material to stiffen and maintain the second shape, and control fluid flow through the fluid flow apparatus.

BACKGROUND

In the drilling and completion industry and for example in hydrocarbon exploration and recovery operations, efforts to improve production efficiency and increase output are ongoing. Some such efforts include preventing undesired fluids or other materials from entering a production borehole. Such materials can pose problems by reducing production efficiency and increasing production costs, for example.

Downhole sand control systems can be employed in an attempt to prevent entry of unwanted materials into a production flow. For example, sand control systems may utilize screens and/or gravel packs to prevent particulates from entering a production string, in order to increase production efficiency and prevent blockages.

SUMMARY

An embodiment of a method of controlling fluid flow in a borehole in an earth formation includes: deploying a fluid flow apparatus in the borehole, the apparatus including a carrier and a shape memory component disposed at the carrier, the shape memory component including a shape memory material having a transition temperature, the shape memory material having a first shape; activating the shape memory material by causing the shape memory material to soften and change from the first shape to a second shape, the second shape configured to cause the shape memory material to control fluid flow; and deactivating the shape memory material by applying a deactivation fluid to the shape memory material, the deactivation fluid configured to cause the shape memory material to stiffen and maintain the second shape, and control fluid flow through the fluid flow apparatus.

An embodiment of an apparatus for controlling fluid flow in a borehole in an earth formation includes: a carrier configured to be deployed in the borehole; a shape memory component disposed at the carrier, the shape memory component including a shape memory material having a transition temperature, the shape memory material having a first shape, the shape memory material configured to soften and change from the first shape to a second shape in response to a stimulus, the second shape configured to cause the shape memory material to control fluid flow; and a deactivation device including a fluid source, the deactivation device configured to apply a deactivation fluid from the fluid source to the shape memory material, the deactivation fluid configured to cause the shape memory material to stiffen and maintain the second shape, and control fluid flow through the shape memory material.

BRIEF DESCRIPTION OF THE DRAWINGS

The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:

FIG. 1 depicts an embodiment of a downhole completion and/or production system including a fluid flow control device;

FIG. 2 is a cross-sectional view of the fluid flow control device in an activated state; and

FIG. 3 is a flow diagram depicting a method of controlling fluid flow in a borehole.

DETAILED DESCRIPTION

The apparatuses, systems and methods described herein provide for controlling the flow of fluid in a borehole in an earth formation. A fluid flow control device or apparatus includes a filtration component configured to prevent particulates such as sand from entering a production string during production of oil, gas and/or other fluids from a formation. In one embodiment, the filtration component is made from a shape memory material such as a shape memory polymer (SMP) that is held in a deformed or “deployment” shape. Upon deployment in a selected location of a borehole, the shape memory material is activated to soften into a rubber state and expand or otherwise return to its “remembered” shape. Activation may occur due to the temperature in the borehole (which may be higher than the material's glass transition temperature) and/or due to a trigger that causes the transition temperature to lower to a point below the borehole temperature, such as an introduced or injected fluid or a magnetic or electro-conductive trigger. After activation, a deactivation fluid is injected from the surface, released from a downhole container, or otherwise introduced to the shape memory material to cause the glass transition temperature of the shape memory material to recover or increase, so that the shape memory material stiffens relatively quickly and can retain its shape in the downhole environment.

Referring to FIG. 1, an exemplary embodiment of a downhole completion and/or production system 10 includes a borehole string 12 that is shown disposed in a borehole 14 that penetrates at least one earth formation 16. In this embodiment, the borehole string 12 is a production string. The borehole 14 may be an open hole or an at least partially cased hole having a casing 18, and may be generally vertical or include a deviated and/or horizontal component. A “borehole string”, as used herein, refers to any structure or carrier suitable for lowering a tool through a borehole and/or connecting a tool to the surface, and is not limited to the structure and configuration described herein. A “carrier” as described herein means any device, device component, combination of devices, media and/or member that may be used to convey, house, support or otherwise facilitate the use of another device, device component, combination of devices, media and/or member. Exemplary non-limiting carriers include borehole strings of the coiled tube type, of the jointed pipe type and any combination or portion thereof. Other carrier examples include casing pipes, wirelines, wireline sondes, slickline sondes, drop shots, downhole subs, bottom-hole assemblies, and drill strings.

The system 10 includes a flow control tool or device 20 for filtering or otherwise controlling flow of fluid from the formation and/or annulus into a completion or production string. In one embodiment, the flow control device 20 operates as a sand control or sand screen device. The flow control device 20 is configured to allow fluids from the formation to enter the production string, and also serves to filter or remove solids and particulates (e.g., sand) and/or other undesirable materials from the fluids prior to entering the production string. As used herein, the term “fluid” or “fluids” includes liquids, gases, hydrocarbons, multi-phase fluids, mixtures of two of more fluids, water, brine, engineered fluids such as drilling mud, fluids injected from the surface such as water, and naturally occurring fluids such as oil and gas.

The flow control device 20 includes a shape memory material that allows the flow control device 20 to be deployed downhole when the device 20 has an initial shape, and subsequently activated to cause the device 20 to transform to a different shape. In one embodiment, the flow control device 20 includes a shape memory component 22 configured as a filter to prevent particulates from entering a production string while allowing fluid to pass therethrough. For example, the shape memory component 22 is a porous material such as a foam. In one embodiment, the shape memory component is made from a shape memory polymer (SMP).

Shape memory materials include materials such as SMPs that have the ability to return from a deformed shape (a temporary shape, also referred to herein as a “deployment shape”) to an initial or previous shape (referred to as a “remembered shape”) when activated. In response to a stimulus, the shape memory material softens and returns to the remembered shape (or attempts to return to the remembered shape, but may be constrained). Exemplary stimuli include a temperature change, an electric or magnetic field, electromagnetic radiation, and/or a change in pH. Non-limiting examples of shape memory materials include SMPs such as polyurethane or epoxy SMPs, which may have properties ranging from, for example, stable to biodegradable, soft to hard, and elastic to rigid, depending on the structural units that constitute the SMP. SMPs may also be able to store multiple shapes in memory.

The system 10 may also include one or more packers 24 for establishing a production zone 26 that is isolated from the rest of the borehole 14. Any number of production zones 26 can be established, each having one or more flow control devices 20 therein. Although the production zone 26 is shown in an open hole portion of the borehole, it is not so limited. For example, the production zone can be cased by a solid or perforated casing.

The flow control device 20 may include or be deployed with various other components. For example, the production string can include at least one fluid conduit such as a gravel slurry conduit for introducing gravel into an annulus. Gravel, as referred to herein, includes any type of filtering material that can be injected into a borehole region and includes rock, mineral or other particles sized to prevent sand or other particulate matter in production fluid from passing therethrough.

In FIG. 1, the flow control device 20 is shown in its deployment state prior to activation of the shape memory component 22. In this embodiment, the shape memory component 22 is shaped as a sleeve, band or other annular component that expands toward the borehole wall when activated. The deployment shape is achieved prior to deploying the flow control device 20 by heating the shape memory material (e.g., a foam or other porous material) to a temperature that is greater than its transition temperature, deforming the material (e.g., compressing the foam around a carrier), and returning the temperature to that which is lower than the transition temperature so that the material stiffens or solidifies and retains the deployment shape.

The transition temperature is the temperature at or above which the material transitions from a relatively rigid or hard state (or glass state) to an elastic, soft or rubber state. In the rigid state, the shape memory material substantially maintains its shape. In the rubber state, the material become softer or less stiff, and can return to its remembered shape if it was previously deformed. The material may be activated, so that it changes from the solid to rubber state, by heating the material beyond its transition temperature. For example, if the transition temperature is less than a temperature at a position in a borehole environment, deployment to that position will result in the material becoming rubbery and returning to its remembered shape. In some embodiments, a trigger or stimulus is applied to cause the material state to change. For example, a heat source can be applied to heat the material above its transition temperature. In other examples, a trigger is applied that causes the transition temperature to lower. Examples of such triggers include the application of an electric or magnetic field, application of light or other electromagnetic radiation, and a chemical change such as a change in pH or exposure to certain chemical compositions or activating fluids.

In one embodiment, the shape memory component 22 is made from a shape memory material that can be deactivated by a fluid (referred to herein as a “deactivation fluid”) that can be injected into the borehole 14 or released from a downhole location. Deactivation refers to causing the transition temperature of the shape memory material to increase, or otherwise causing the shape memory material to stiffen or harden. The deactivation fluid can be applied to the shape memory material after activation, to facilitate the shape memory material's return to a stiff or relatively inelastic state in which its shape is maintained.

FIG. 2 is a cross-sectional view of the flow control device 20 in an activated state. The flow control device 20 includes a base pipe or tubular 28 and a plurality of radially and axially placed fluid passages or perforations 30 extending through the base pipe wall. A porous shape memory component 22 (e.g., a SMP foam) surrounds the base pipe 28 or is otherwise positioned between the annulus and the perforations 30 to filter formation fluid flowing from the formation into a flow conduit formed in the production string 12. In this state, the shape memory component 22 has softened to a rubber state and expanded to its remembered shape.

In one embodiment, the flow control device 20 and/or other downhole components are equipped for operable and/or fluid communication with a surface unit 32. The surface unit 32 may be used to control various aspects of production, such as controlling pumps, monitoring production, controlling injection of fluids (e.g., gravel slurry, production fluids, fracturing fluids, etc.) and controlling operation of downhole tools. The surface unit 32 may include one or more processing units 34, and the flow control device 20 and/or other components of the production string 12 may include transmission equipment to communicate with the surface unit 32.

In one embodiment, the fluid control device 20 is connected in fluid communication with a fluid source, such as a surface fluid storage unit 36 or a fluid container 38 disposed downhole as part of the flow control device 20 or at another downhole location. The fluid source may be configured to inject deactivation fluid into the borehole string and/or into an annulus between the borehole string 12 and the borehole wall. Control of injection of the of the deactivation fluid may be affected by the surface unit 32, a user, or a local or remote processor.

Characteristics of the fluid flow control device 20, such as shape, configuration and deployment mechanism, are not limited to those embodiments described herein. The shape memory material may take any suitable deployment shape and, in one embodiment, deform into any desired shape upon activation. For example, the shape memory material can be made into one or more plugs to be deployed at any location of a wellbore, borehole string and/or casing string.

FIG. 3 illustrates a method 40 of controlling fluid flow in a borehole in an earth formation. The method 40 includes one or more stages 41-45. The method 40 is described in conjunction with the fluid flow control device 20 described herein, but may be used with any apparatus or system that includes shape memory material. In one embodiment, the method 40 includes the execution of all of stages 41-45 in the order described. However, certain stages may be omitted, stages may be added, or the order of the stages changed.

In the first stage 41, at fluid control device or apparatus including least one shape memory component, such as a conformable band or annular structure made from a shape memory material, is disposed on or in a downhole carrier, such as a production string or tubing. The shape memory material has a first transition temperature. In one embodiment, the shape memory material is heated to a temperature at or near the first transition temperature, and the band is deformed to a deployment shape suitable to allow for deployment of the device downhole. The fluid control device is described as the fluid control device 20, but is not so limited.

In one embodiment, the shape memory material is a cellular or porous material such as a compressible foam having pores such as bubbles, cells or other porous structures having a size and/or shape that allows formation and/or production fluid (e.g., oil, gas and water) to pass through while preventing particulates such as sand from passing through.

For example, a SMP foam such as a polyurethane foam or other shape memory material is molded or otherwise formed into a shape memory component 22 having a desired first shape (the remembered shape), such as the shape of an annular band or sleeve that can be disposed on a base pipe or other carrier. The component 22 has a thickness sufficient to extend from carrier to a borehole wall or casing, and conform to the borehole wall or casing. The SMP foam has a defined transition temperature, referred to in this example as a glass transition temperature or Tg. The SMU foam component is then heated close to the Tg, and a force is applied to the component to reshape it into a different configuration or shape (a temporary or deployment shape) such as a narrow band. The reshaped component is then cooled below the SMP's Tg and the force removed. This deformed component will now retain the deployment shape until the temperature of the component is raised to the Tg, at which point shape recovery will begin and the component will attempt to return to it's original shape or if constrained, the component will conform to a new constrained shape, such as the annulus between the carrier and borehole wall.

In one embodiment, the shape memory material has a first transition temperature that changes into a second lower transition temperature in response to a trigger.

In the second stage 42, the fluid control device 20 is deployed downhole, for example, to a region of an earth formation. For example, the fluid control device is deployed with production tubing or other production or completion components.

In the third stage 43, the shape memory component 22 is activated to cause the shape memory material to attempt to revert to its original shape. This activation may occur due to elevated temperatures in the borehole that meet or exceed the material's transition temperature, such as the Tg of the SMP foam.

In one embodiment, a trigger is applied to the component 22 to cause the shape memory material's transition temperature to change from a first transition temperature to a second transition temperature that is approximately equal to or lower than the borehole temperature. The trigger may encompass any suitable technique, such as the introduction of fluid that causes a reduction in the transition temperature, a change in chemical composition of the production fluid by introduction of fluids from the formation or a user, application of an electrical current, and application of electrical or magnetic fields.

In the fourth stage 44, a deactivation fluid is applied to the component 22 after the component has expanded to the borehole wall or expanded to a selected radial location in the annulus. Application of the deactivation fluid causes the transition temperature of the component to increase. For example, if the transition temperature was previously lowered by a trigger, the deactivation fluid causes the component to recover its original transition temperature more quickly than it would naturally (e.g., due to dissipation of activation fluid or the normal amount of time that it takes to recover after the trigger is removed). If the component 22 was activated by the heat of the borehole, the deactivation fluid acts to raise the transition temperature to a point above the borehole temperature to allow the component to solidify.

For example, an engineered completion fluid is pumped downhole, e.g., through the production string and through the component to raise the component transition temperature. A completion fluid is typically a liquid injected into the borehole prior to initiation of production. For example, a completion fluid is used to facilitate pre-production operations, such as setting production liners, packers, downhole valves or shooting perforations into the producing zone. Completion fluid may also be provided to control a well should downhole hardware fail, without damaging the formation or downhole components. Any completion fluid that raises the transition temperature may be used. Exemplary completion fluids are brines (e.g., chlorides, bromides and formates), however any suitable fluid having proper density and flow characteristics may be used. In one embodiment, the completion fluid includes constituents such as potassium chloride, calcium chloride and sodium bromide.

Other fluids may be used as a deactivation fluid. For example, drilling fluids or stimulation fluids (e.g., hydraulic fracturing fluids) can be employed as deactivation fluids.

The deactivation fluid can act in numerous ways. For example, the deactivation fluid can react directly with the shape memory material to raise the glass transition temperature. In another example, the deactivation fluid acts to deactivate or neutralize the effects of a softening agent or the activation fluid.

In the fifth stage 45, production fluid is produced from the borehole. The production fluid is pumped or allowed to migrate from the formation, through the shape memory component 22, and through the production string. Sand or other undesirable particles are filtered from the production fluid as it is produced.

The systems and methods described herein provide various advantages over existing processing methods and devices, by allowing for quick and efficient deployment of sand management systems or other fluid control devices or systems. Use of the deactivation fluid allows for quicker recovery and solidification of a filtration component, which reduces the chance of collapse and also allows for faster onset of production. For example, when a filtration component is in a rubber state, variations in pressure or fluid flow could cause undesirable deformation. The embodiments described herein reduce the potential of such collapse by reducing the amount of time that the component is in the rubber state.

While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications will be appreciated by those skilled in the art to adapt a particular instrument, situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention. 

1. A method of controlling fluid flow in a borehole in an earth formation, comprising: deploying a fluid flow apparatus in the borehole, the apparatus including a carrier and a shape memory component disposed at the carrier, the shape memory component including a shape memory material having a transition temperature, the shape memory material having a first shape; activating the shape memory material by causing the shape memory material to soften and change from the first shape to a second shape, the second shape configured to cause the shape memory material to control fluid flow; deactivating the shape memory material by applying a deactivation fluid to the shape memory material, the deactivation fluid configured to cause the shape memory material to stiffen and maintain the second shape, and control fluid flow through the fluid flow apparatus.
 2. The method of claim 1, wherein activating the shape memory material includes exposing the shape memory material to a downhole temperature that is equal to or greater than a transition temperature of the shape memory material, and deactivating the shape memory material includes increasing the transition temperature to a value that is greater than the downhole temperature.
 3. The method of claim 1, wherein activating the shape memory material includes applying a trigger to the shape memory material that is configured to reduce a transition temperature of the shape memory material to a value that is less than a downhole temperature.
 4. The method of claim 3, wherein deactivating the shape memory material includes increasing the transition temperature to a value that is greater than the downhole temperature by directly exposing the shape memory material to the deactivation fluid.
 5. The method of claim 3, wherein deactivating the shape memory material includes neutralizing the trigger.
 6. The method of claim 3, wherein deactivating the shape memory material includes causing the transition temperature to recover at a rate that is faster than a normal recovery rate.
 7. The method of claim 1, wherein the shape memory material is configured to control fluid flow by filtering particulate matter from fluid produced by the earth.
 8. The method of claim 7, wherein the shape memory material is a porous material configured to prevent particulates from entering a production string, the first shape is an annular shape surrounding the carrier, and the second shape is an expanded shape having an annular thickness that is greater than the first shape.
 9. The method of claim 7, wherein the shape memory component is a sand screen component.
 10. The method of claim 1, wherein the activation fluid is a completion fluid configured to be disposed in the borehole prior to initiating production of fluids from the formation.
 11. An apparatus for controlling fluid flow in a borehole in an earth formation, comprising: a carrier configured to be deployed in the borehole; and a shape memory component disposed at the carrier, the shape memory component including a shape memory material having a transition temperature, the shape memory material having a first shape, the shape memory material configured to soften and change from the first shape to a second shape in response to a stimulus, the second shape configured to cause the shape memory material to control fluid flow; and a deactivation device including a fluid source, the deactivation device configured to apply a deactivation fluid from the fluid source to the shape memory material, the deactivation fluid configured to cause the shape memory material to stiffen and maintain the second shape, and control fluid flow through the shape memory material.
 12. The apparatus of claim 11, wherein the stimulus includes exposure of the shape memory material to a downhole temperature that is equal to or greater than a transition temperature of the shape memory material, and the deactivation fluid is configured to increase the transition temperature to a value that is greater than the downhole temperature.
 13. The apparatus of claim 11, wherein the stimulus includes application of a trigger to the shape memory material, the trigger configured to reduce a transition temperature of the shape memory material to a value that is less than a downhole temperature.
 14. The apparatus of claim 13, wherein the deactivation fluid is configured to increase the transition temperature to a value that is greater than the downhole temperature via direct exposure of the shape memory material to the deactivation fluid.
 15. The apparatus of claim 13, wherein the deactivation fluid is configured to neutralize the trigger.
 16. The apparatus of claim 13, wherein the deactivation fluid is configured to cause the transition temperature to recover at a rate that is faster than a normal recovery rate.
 17. The apparatus of claim 11, wherein the shape memory material is configured to control fluid flow by filtering particulate matter from fluid produced by the earth.
 18. The apparatus of claim 17, wherein the shape memory material is a porous material configured to prevent particulates from entering a production string, the first shape is an annular shape surrounding the carrier, and the second shape is an expanded shape having an annular thickness that is greater than the first shape.
 19. The apparatus of claim 17, wherein the shape memory component is a sand screen component.
 20. The apparatus of claim 11, wherein the activation fluid is a completion fluid configured to be disposed in the borehole prior to initiating production of fluids from the formation. 